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new to me, 98 M3


cpandrewschmidt

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Morning all, time to pick your brains again.  So, I've never been able to figure out my CEL issue and I'm determined.  If you'd read back you'd notice car seems to run fine but I'm running rich.  Quick summary:  I get mixture deviation codes on banks 1 and 2 with negative fuel trims.  I'll clear codes and monitor the live data.  LTFT starts at zero then works its way to the -8.6% threshold fairly quickly where DME overrides and trips the CEL.  I've noticed bank 1 gets there about -1% more quickly than bank 2, but then they both eventually get to the -8.6%  I understand this to mean I don't have a vacuum leak as that would cause lean fuel trims (positive)  Plus I've tested numerous times with smoke for any intake leaks.  

Things I've done within the last 3-8,000 miles: valve cover gasket, vanos seals, fixed intake boot leak, fuel filter, new FPR, all new O2 sensors, sent out injectors for testing (tested good, no leaks), spark plugs, boots, coil packs.  Unplug MAF and confirm idle change, so appears to be working.  Cam shaft position sensor.  The latest was the cam shaft position sensor.  Old one was definitely compromised. It had frayed exposed wires.  Light stayed off for 2 weeks and a lot of driving so I thought I found it.  Then, came back.  Same codes.  

This brings me to a couple ideas.  

1.  Possible exhaust leak - I've read if the leak is on the exhaust side before the o2 sensors that can cause rich conditions.  I'll be confirming tomorrow if there's a leak at the manifold or elsewhere.  Assuming that's ok onto my next ideas.

2.  When I got the car it was needing maintenance, valve cover leaked, intake, etc.  My thought is perhaps the tune was done with these leaks causing causing misleading lean conditions.  Now that I've patched them up, cleaned up fuel filter, fpr, etc it's just flowing that much better and running rich.  My question is does anyone here know if you can tune injectors to not run as much fuel?  Anyone here know how to for some $?

3.  DME compromised?  There's a guy on bimmerforums that'll re-flash the tune onto a new DME but that's $380 and i don't want to spend that if it's fine.  Car doesn't experience any other symptoms so I assume it's OK? 

4.  Timing issue from vanos job.  I've done it now 3 times checking my work and using the compressed air to confirm movement.  Seems OK.  But with bank 1 showing signs first maybe intake CAM is still off?  Are there computers out there that can sense that?  I did job using blocks and all lines up.   

5.  Coolant temp sensor?      

I'm basically out of mechanical ideas to fix / test.  Only thing I haven't changed is the CCV.  I don't think that would cause a rich condition.  I've cleaned out ICV.  I was OK replacing all the other parts because they were maintenance items anyway, but now I'm out of things to fix.

Looking forward to hearing all your thoughts and wisdom!  Willing to pay money for help.  I just don't want to take to the deal because they'll do all the same things I've already done, unless their programs are more capable than what I have. 

Thanks, Andrew

PS - detailed and put summer tires on, so you all can blame me if we get 6" of snow Friday night.    

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Never not had a CEL. but i didn't know enough back then to look at fuel trim ratios.  was focused on vacuum leak stuff as that is what everyone always talks about.  Since I bought from out of state I assume previous owner cleared codes before selling.  1st thing I noticed were 02 sensors were actually disintegrated post CAT.  did those 1st but still didn't fix CEL.  Then did valve cover as that was leaking oil.  Then the rest of the list above as other preventative maintenance along the way.  Still haven't pin pointed it.  Ordered up a coolant temp sensor for the block as they are only $25 bucks.  Figured why not.  Will try to put that in tomorrow too, but supercharger might make that a difficult job.  

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tried to check for exhaust leaks around manifold / before 02 sensors.  Nothing that I could find.  Couldn't get Coolant Temp sensor installed without removing supercharger.  Highly doubt it's that anyway.  

So, really thinking this thing it just putting too much fuel into it since I can't think of anything else to check.  Everything else is solid, no leaks etc.  Guess that brings me back to what you all might know about tuning injectors?  I'm not 100% sure what ones i have.  They have a blue O ring on them.  Guess I'll have to pull one to confirm.    

If there's anyone that can help with computer stuff that's where my knowledge stops.  Willing to pay for help!  

Andrew

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the only two things I can think of that would be worth trying at this point are:

get the brand/part number of the injectors so you can verify the flow rate. Then take a look at the chip in the ECU and see if it has any info that may help you match it to the injectors (may have a GIAC 24# label or something). 

 

the next item is, have you tried the chip in another ecu in the car to rule out a wonky ecu?
 

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Haven't swapped DME at all.  Don't have an extra, or a car to swap into.  Are there other ways to test DME?  When you say ECU, it's the same as the DME, right? 

For Injectors all I know about them if from when I sent them in.  He said "They are "weber style"  After cleaning The dynamic flow test ( 12 ms pulse width / 2400 rpm / 25 seconds ) had flow rates of 100 up to 104 cc.s across the board. The injector flow balance is now very close to 3.8 %.  He said they all performed flawless in all the tests and All of the injectors held pressures over 80 psi without leaking a drop, and their spray patterns were perfect."

I'll pull one soon to get the model # off them. 

On my DME.  I pulled it a few weeks ago to look at it.  I've read about corrosion issues.  Sure enough, it was pretty corroded.  I thought that would be it.  Attached are before and after cleaning pictures, along with the "chip" side, which was clean.  I cleaned it real well with electrical cleaner.  No difference in how car performed and it did clean up well.  I would guess it was still OK, nothing looked fried on the chip side of things.  No visible burn through marks on the board.  Also, all live data systems like o2, stft, ltft, MAF etc all get readings when plugging in my code reader.  So, they appear to be reading fine.  

 

DME before.jpg

DME after.jpg

DME chip side.jpg

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Yeah, DME/ECU, same thing depending on how german im feeling at the moment

My mistake by saying " chip"  its OBD2 which means it needs a reflash to install the supercharger tune on it. Im not too worried about the ECU being bad. It would just be great to know for sure what size injectors are on there and what size the software is for as kind of a "back to square one" type of check. You can diagnose all you want but if the tuning is wrong for the injectors then you will never luck diagnosing it and throwing parts at it. 

@m42b32   can your newfound flashing skills come to play here? I dont remember seeing anything for injector size in Tuner Pro, but is there any way to verify injector size on the tune with what you have?
 

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25 minutes ago, snap said:

@m42b32   can your newfound flashing skills come to play here? I dont remember seeing anything for injector size in Tuner Pro, but is there any way to verify injector size on the tune with what you have?

@Daggerty you tuned your e36 with the stock DME right? Were you able to find definition files for your car or did you work around it? I have yet to find anything useful for ms41.2 (s52). 

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Yes the newest download is on romraider which for whatever reason it won't let me log on and the admin won't respond to my emails. I have some of the definitions.

I don't know if I would be able to get anything of of the DME because big name tuning companies lock them or whatever. So Joe Shmoe, no pun intended, can't steal their tune.

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I'm using an "autolink" scanner from a friend, same one on page 2 of this.  There's a section for freeze frame data.  It shows: DTCFRZF, FUELSYS1, FUELSYS2, LOAD_PCT(%), ECT(degreeF), SHRTFT1(%), LONGFT1(%), SHRTFT2(%), LONGFT2(%), RPM, VSS(mph)  - what should I look for in that?  Live data seems to show more categories.  

I also have the ability to datalog from http://bimmersoftware.com/bmwlogger  it shows pretty much same stuff as the live data along with Vanos IN/OUT

Hopefully that Admin gets back to you :)

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Can you watch a trend/log of ignition timing?  Observe it on a working car so you know what it should look like and then observe on the BMW and see if you see odd drops.  That's what i have seen when ECU detects knock and pulls timing, but you can usually feel it.  My old Maxima would pull timing and feel like it was misfiring without premium gas and I was thought something was wrong until I watched the timing log and realized it was just protecting itself.

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I have a datalog from a couple months ago saved in excel.  Can't drive the car the next few days because of the snow.  Jinxed us with putting summers on, sorry........

I tried to attach it here, not sure if it will work.  In looking at the IGN category it starts out around the 15 mark and hovers there for a while, then goes up to the 30 ranges and hovers around there.  I noticed at lines 8781, 9195, 9641, and 11785 it starts to drop down to 1 along with my Lamba sensors zeroing out.  Could be something, could be nothing.  I'm not really sure.  

Again, this log was from a little bit ago.  I assume if I do a few more runs it would overall look similar.  I'll do that when I can drive again with the weather.  If you all can take a peak at this and let me know your thoughts that'd be great.  

Datalog.csv

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I tried exploding it up trending RPM, TPS, and IGN, it is hard to tell but it seems ok.  It is most useful to watch while riding in the car, and watching it react to throttle input.  Geneally you will see the timing increase as RPM increases, although the more throttle is opened will cause it to drop off.  If there is knocking detection you will see small spikes downward on the ignition timing.  

I saw this best on a friend's G8 GT that he had tuned but something wasn't right and heavy throttle around 4k would knock, you could hear it, so I used my OBDLink bluetooth device and we could see it pulling timing even slightly before the audible knock was apparent.

For a relatively cheap device I like the OBDLink MX, it's more expensive than cheap ebay bluetooth devices but it works great and the app that is free but only works with their device is quite good.  Just connect your phone and choose PIDs to graph.  I have not used it with a BMW though.

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  • 2 months later...

working on the convertible.  Subframe out, thanks for the tips @Jdesign .  It dropped down just fine with out the bar trick.  Guess I got lucky but this job still sucks btw!  Had issues getting it to clear the driveshaft.  Ended up having to undo the back half of that to get it to clear and drop.  Have some nice smashed fingers.   

I'm doing all my bushing while it's out.  Ordered new Ground Control System Coilovers as well since my JOM's sucked.  

Also doing wheel bearings.  I forgot to losen my axel nut while it was on the car.  Am I going to be screwed trying to get that loosened?  Wonder if that will have to wait till things are buttoned back up?  

subframe.jpg

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1 hour ago, Earl said:

Have a half inch impact? It should bust those loose pretty easily once you get the locking plate out. 

^ This. A decent 1/2" impact (and soaking in a bit of penetrating oil for good measure) should make quick work of those axle nuts

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Got the nut off no problem with impact wrench.  Got to buy a new one :) I finally got this putting it back in last night.  This job sucked.  Part of the bearings froze onto the hub, had to cut and hammer and wedge in a vice to get it off.  2 hours alone messing with that.  Bushings were all ok to put back in.  Press was a life saver.  No idea how anyone could do this without one.  Some pictures of the carnage along the way.  Saw online people burning their bushings out.  That proved to be pointless because you still had to press out the metal sleeve.  But I'm sure my neighbors appreciated the fire.  Smashed my hand with a hammer and have taken more showers to get grease off in a week than I would normally in a month.  Picture doesn't do justice to how dirty I really was!  New GC Coilovers arrive today.  Will get the rears in and button everything back up.  Will get to the fronts in the next week or two.  I have to cut 2" of the sleeve and reweld for the type of shocks I got.  Gotta find a welder.  I'll post more pictures when all done! 

vert subframe out.jpg

vert subframe 1.jpg

vert subframe 2.jpg

vert subframe face.jpg

hand.jpg

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